"Lost Core" from Bühler: New die casting technology opens up a wide range of applications

Current trends such as lightweight construction in the automotive industry or the pressure to manufacture increasingly better products at lower cost require creative die casting solutions. An innovative answer to this is the "Lost Core" technology (salt core technology), which thanks to its completely new possibilities allows for a diverse range of applications. More than 100 developers and users from around the globe will able to learn about these multifaceted opportunities at a symposium in mid- November at the Bühler headquarters in Uzwil (Switzerland).

What the automotive industry is calling for is cost reduction, integral design (reduction in the number of components) and higher productivity. The "Lost Core" technology opens up diverse opportunities for this. With this technology certain parts of the component to be cast are recessed with a salt core which is then rinsed out again. This makes it possible for permanent mold cast and sand cast components to be replaced and at the same time the full benefits of die casting such as material savings, shorter cycle times and reduced post-processing can be reaped. "Lost Core" also enables the development of completely new components. The internal shaping can comprise complex designs, the combination of multiple components into one single unit enables high function integration, and the increased design freedom allows for a completely new component design.

Lost Core technology in the Bühler process

The Bühler Lost Core process begins with the component design for the salt core application, followed by the mold, aluminum part and salt core concepts. The behavior of the liquid salt and aluminum in the mold as well as the quality of the component can currently be simulated by software. This eliminates the need for subsequent costly adaptations of the mold. In the creation of the salt core which determines the internal shaping, the optimal salt solution plays a crucial role in ensuring the stability of the core while simultaneously enabling its subsequent removal.

The salt core and the aluminum component are produced on a die casting machine with real-time control. This prevents damage to the core during re-casting. The core is removed by pressurized water. Bühler has the necessary know-how and equipment for the successful application of Lost Core technology and is in a position to support the complete process from the initial idea to the production stage.

A well-attended Symposium

In view of its diverse possibilities, there is naturally great interest in the new technology. This was also demonstrated by the well-attended Bühler symposium in mid-November. The 100 plus participants, including prominent representatives of the automotive industry and its suppliers, were won over by the advantages of the Bühler Lost Core process. A concrete project was simulated over all stages one by one to promote better understanding. The economic aspects were also not ignored and were emphasized very clearly by Dr. Andreas Hennings and Georg Habel from the renowned Bocar die casting company. A further highlight was that the participants were also able to experience the various process phases live. Dr. Lothar Kallien from the University of Aalen supplemented the program by presenting the results of a 3D free-form surface project which was implemented using the Lost Core technology.

The final round of discussions provided an opportunity to talk about what was seen and heard in greater depth, to share experiences, and to discuss the potential of this technology. As a result all of the participants were in agreement: Lost Core will fully open up new opportunities in the coming years and is therefore facing a promising future.